void main() { long int n,i,j,sum=0; clrscr(); printf(\"\\n PLEASE ENTER THE VALUE OF N: \"); scanf(\"%ld\",&n); printf(\"\\n SUM = \"); for(j=1,i=12;j<=n;i=i+20,j++) { if(j%2==1) { sum=sum+i; if(j==n) printf(\"%ld\",i); else printf(\"%ld - \",i); } else { sum=sum-i; if(j==n) printf(\"%ld\",i); else printf(\"%ld + \",i); } } printf(\"\\n\\n THE SUM IS %ld\",sum); getch(); } **************************** OUTPUT ********************************* PLEASE ENTER THE VALUE OF N: 9 SUM = 12 - 32 + 52 - 72 + 92 - 112 + 132 - 152 + 172 THE SUM IS 92 *********************************************************************